Here's a video of my computer. It's calculating the Fibonacci sequence, and once it overflows the numbers turn red and the program restarts. It is running quite efficiently. This is partly due to minimal nesting of chips, but I also trimmed the microinstructions down to 4 instead of 5. The clock-synchronized flip-flops in the counters means it rarely runs into errors.
I skipped adding RAM to the system mostly to make programming it easier, but you could easily replace the memory ROM with RAM. I also didn't add a flag registry and just fed the carry bit directly into the instruction register.
Here are the project files and operations if you want to experiment with it. (I just realized that in the video the steps are counting to 5, but I've fixed that in the files)
After making this system, I'm really starting to bump into the limitations of an 8-bit system, such as 4-bit address allowing for only 16 memory locations. I'm tempted to make a 16 bit system next.